Abstract: Milk and purple sweet potato were used to produce purple potato supplemented cheese and the effect of the fermentation process on the change in dietary fiber content was investigated. Purple sweet potato, fermentation temperature and time were optimized using one-factor-at-a-time method and response surface methodology. The contents of nutrients and dietary fiber in cheese samples were measured by the national standard methods. The results indicated that the optimal process parameters were obtained as follows: 4% purple sweet potato flour, and fermentation at 42 ℃ for 8 h. The cheese prepared using the optimized conditions consisted of 19.79% protein, 15.62% fat and 46.75% moisture and contained 2.97 CFU/g of mold and its titratable acidity 78.03 °T, which met the national standards. In addition, the cheese had a dietary fiber content of 0.106 mg/100 g and its structure and texture was uniform. It was good in appearance with a light purple color and had the characteristic aroma of milk and the unique aroma and flavor of purple sweet potato.

Key words: purple sweet potato; cheese; fermentation process; titratable acidity; dietary fiber

摘要： 以牛乳和紫薯作为原材料，制作紫薯奶酪，并分析发酵工艺对膳食纤维含量变化的影响。通过单因素和响应面试验优化紫薯粉添加量、发酵温度与发酵时间，通过国标方法对采用最佳发酵工艺制备的紫薯奶酪中的营养成分及膳食纤维含量进行测定。结果表明：制备紫薯鲜奶酪的最优工艺参数为紫薯粉添加量4%、发酵温度42 ℃、发酵时间8 h；该条件下制成的紫薯鲜奶酪的蛋白质含量为19.79%、脂肪含量15.62%、水分含量46.75%、霉菌总数2.97 CFU/g、滴定酸度78.03 °T，均符合国家标准，膳食纤维含量为0.106 mg/

关键词: 紫薯；奶酪；发酵工艺；滴定酸度；膳食纤维